EP1097799B1 - Tape laying unit for depositing a band of composite material - Google Patents

Description

The present invention relates to a head intended for the application of laminar strips of what is called a composite, with which, and by the compact superposition of which laminated parts, of the panel type, which are used in aeronautical, naval industries, etc.

US Patent DEG 4,696,707 to "The Ingersoll Milling Machine Company", as well as European Patent 0,333,010 to "Cincinnati Milacron Inc." and patents 9302506 and 9402102 belonging to the applicant of the present invention relate to this type of head.

These wrapping heads include compacting elements which are those which press on the strip to be applied, by exerting a pressure on the latter, so that it is fixed on the upper layer of the part being formed, to achieve compaction by uniformizing in the greatest extent possible incorporation of the strip on the surface of the corresponding panel, in order to prevent air bubbles from forming in the layer formed, since, for certain applications such as those in the aeronautical sector, such bubbles would render the panel containing them unusable.

For the compaction to be as effective as possible, it is necessary that the compacting element adapts to any curvatures and irregularities that the panel has in its surface and that, in addition, the compacting element pushes on the belt being d application with adequate force.

To this end, it is already known to produce the compacting elements with a segmented structure, in which the different segments are held in their position by mechanical means, which is of a very complicated construction and, moreover, of a poor reliability in operation.

In patents 9302506 and 9402102, there is on the other hand a solution for the construction of the compacting elements comprising an embodiment of identical parts arranged one next to the other in a correlation such that each part moves by sliding by with respect to the adjoining parts, in a movement independent of each of them, said parts forming recesses which as a whole define housings in which there are tubular conduits where a pressurized fluid circulates.

Tubular conduits are common to all the parts of the same compacting element and have sufficient rigidity to keep the different parts in the stable alignment position, one next to the other but, at the same time, they are flexible, so that, if one presses externally on any of the parts, there is a displacement of the latter by elastic deformation of the tubular conduits, which absorb said displacement. When the external thrust on the displaced part disappears, the pressurized fluid inside the tubular conduits causes it to return to the initial position, the part then returning in alignment with the others.

In this way, each compacting element defines a leading edge which adapts to the curvatures and irregularities of the panel that is formed with the strips being applied, thereby achieving uniform compaction of the entire surface. US Patent 4,591,402 describes a wrapping head according to the first part of the main claim. In this known wrapping head, there is a gland 131 and a pressure element 145 which are not independent, but on the contrary which move at the same time so that the gland acts when the pressure element does not act , and vice versa.

According to the present invention, there is provided a new wrapping head intended for the function already indicated above, in which provision has been made for construction features which make it advantageous from the functional aspect.

This head, which is the subject of the invention, has the particularity that the compacting means consist of a discharge element and a pressure element, which act independently and successively on each application zone, the two elements being able to be toggled between respective positions of work and withdrawal, so that the gland first performs the application of the strip by adapting to the corresponding surface, having for this a deformable construction depending on the surface; while the pressure element then comes into action by compressing the strip applied with force on the application surface. In this way, perfect compaction of the strips is obtained on the application surface. More particularly, the present invention provides a wrapping head for applying strips of composite of the type formed by a rotary assembly which can be tilted, comprising compacting means intended for pressing a strip composed of an upper layer of composite and of a paper support sheet and which is conveyed from a supply reel, the compacting means being constituted by a presser and by a pressure element, which can both be tilted between respective working and withdrawing positions, the gland coming into action in the first place to fix the upper layer of composite of the strip on the application surface, while the pressure element then acts, by pressing the composite layer with force against the corresponding surface to carry out compaction, characterized in that: the gland and the pressure element are arranged so that they can be actuated independently and successively on the application area, the gland being mounted on a tilting support, which can be tilted by means of actuating cylinders, to give the working and withdrawal positions of said gland, and the pressure element being mounted on a tilting support, which can be actuated in tilting by means of actuating cylinders to give the working and withdrawal positions of said pressure element while other cylinders enter action for pressing said pressure element with force against the application surface in the working position.

The proposed head further comprises a device for centering and aligning the strip with which the errors to which the misalignment of the strip gives rise and which accumulate during the application process are avoided.

For this, the reel holder which carries the carriage for conveying the strip is movable as a whole in the axial direction, thus making it possible to adjust the situation of the carriage for its centering with respect to the alignment of the application; however, on the path of the tape conveyance to the application area, conductive guides are arranged, which are adjustable in width to situation of the carriage for its centering in relation to the alignment of the application; however, on the path of the tape conveyance to the application area, are arranged conductive guides, which are adjustable in width for adaptation to the band used and in turn adjustable in position for centering in relation to the alignment of the application.

In the head, there are also provided cutting means with which the composite strip is obtained in the manner necessary for it to come off safely, respecting the paper backing sheet so that it does not break. not and that it can be collected without interruption.

Said cutting means are constituted by two cutting mechanisms, which comprise a rotary actuation by motor, a longitudinal displacement actuation by screw and an elevation displacement actuation by cylinders, allowing cuts to be made along any trajectory and with a total cutting depth of the composite strip, up to the paper backing sheet without the latter being affected by a risk of rupture.

The rotational and tilting movements of the head used for the wrapping process are controlled with double pinion mechanisms on a take-up ring, by means of which total precision is obtained, with no play in the reversal of the movement. .

On the path of the strip towards the application area, two boxes are provided provided with photodiodes detectors by means of which a perfect control of the strip is carried out, to prevent that one comes to apply defective parts.

The speed of the conveyor belt towards the application area is controlled by means of a transfer encoder roller by means of which a control of the actuation of the advance of the belt is effected, to maintain a speed arrival constant at the application area, remaining independent of the variables linked to the exhaustion of the supply coil.

With all this, we obtain a wrapping head which offers characteristics which are certainly very advantageous thanks to the precision which we obtain in the various aspects for carrying out the application of the strips of composite with total perfection.

Figure 1 shows a perspective of the entire wrapper head proposed.

Figure 2 is a side view of said head object of the invention.

Figure 3 is a corresponding front view of the head.

FIG. 4 shows an enlarged detail of the carrier assembly of the reel for supplying the strip to be applied and of the reel for receiving the protective paper forming the rest of the strip applied.

FIG. 5 shows a detail of the guide assembly of the strip to be applied, where the upper guide and the lower guide are seen with their adjustment mechanisms.

Figure 6 shows an enlarged detail of the upper guide guide adjustment mechanism.

Figure 7 is an elevational view of the cutting mechanism.

Figure 8 is a perspective view in plan of the aforementioned cutting mechanisms.

Figure 9 is a cross section taken as shown in the previous figure.

FIG. 10 is a diagram of all of the compaction means formed by an independent gland and presser.

FIGS. 11 to 14 represent a sequence of the process of applying a strip, showing the successive positions of the compacting means.

FIG. 15 is a detail of the detector boxes provided for controlling the strip to be applied.

FIG. 16 is a detail of the encoder roller for controlling the speed of conveyance of the tape to the application area.

The present invention relates to a wrapping head, of the type used for applying composite strips in the formation of laminated parts or panels by superimposing and compacting the strips.

These heads comprise a reel holder (1) in which is mounted a reel (2) which carries the strip (3) to be applied, said strip (3) being led towards the application area where pressure means come into action which carry out the compaction of the composite strip (3.1, FIGS. 11 to 14) on the surface in formation, while the corresponding paper support sheet (3.2) is led to be wound on a take-up reel (4) arranged on a respective reel holder (5).

According to the invention, the means provided for compacting comprise a discharge element (6) and a pressure element (7), which are arranged independently on respective supports (8 and 9), as seen in the figure. 10.

The plugger (6) is constituted by an element which forms a flexible front actuator, allowing adaptation to the application surface of the composite (3.1), in a manner which makes it possible to absorb the irregularities of said surface, by pressing evenly across the entire line of the application.

Said gland (6) can be tilted with its support (8) by means of cylinders (10), with the possibility of pivoting between a working position on the application zone and an inoperative position in a retracted position with respect to said zone. 'application.

The pressure element (7) is constituted on its side by a rubber roller which is also mounted so that it can be tilted, being able to pivot by means of cylinders (11) between a working position in the area of application and an inoperative position in a retracted position relative to said application zone, while by means of other cylinders (12), it is possible to produce a high pressure of this roller on the application zone, in the position of job.

In this way, the process of compacting the composite strip (3.1) on the forming surface takes place according to the sequence illustrated in Figures 11 to 14.

In a first phase, the composite strip (3.1) is pressed on the corresponding surface by the gland (6), as shown in Figure 11, the pressure element (7) remaining in the inoperative position.

Then, under the action of the cylinders (11), the pressure element (7) is placed in position to enter into action, as shown in Figure 12, the gland (6) then tilting in the inoperative position, under the action of the cylinders (10), as shown in Figure 13.

And, finally, the pressure element (7) is caused, by means of the cylinders (12), to exert a strong pressure on the application area, as shown in FIG. 14, thereby generating perfect compaction of the composite strip (3.1) on the corresponding surface.

Under the effect of the withdrawal of the cylinders (12) and the cylinders (11), the pressure element (7) then switches to the inoperative position, while with the cylinders (10), the gland (6) is tilted ) in the working position, so that the initial position is shown in FIG. 11, for compacting a new segment of the composite strip (3.1) in the rest of the application process.

The aforementioned compacting process could also be carried out with two elements (6) and (7) identical, but arranged so that one exerts a pressure of laying of the composite strip (3.1) and that the other exerts a stronger pressure in order to make the compaction effective.

The guide of the strip (3) from the supply reel (2) to the application area is carried out by passing over guides (13) and (14), which are equipped with an air supply under pressure, which creates an air cushion on which the strip (3) rests in its sliding, thus avoiding friction.

Said guides (13) and (14) are formed by a set of sectors which produce a composition adjustable in width, which makes it possible to perfectly adjust each of the guides (13) and (14) to the width of the strip (3) used. in a given case; each of the aforementioned guides (13) and (14) having for this purpose an actuator (15, FIG. 5) which makes it possible to move the respective constituent assembly, by modifying the width, by bringing together or simultaneously moving the corresponding end portions relative at the center line.

These guides (13) and (14) also have, as can be seen in FIG. (6) which relates to the guide (13), stops (16) and (16.1) which serve as lateral edges for guiding the the strip (3), said stops (16) and (16.1) determining two guide widths, for example for strips (3) of the order of 150 millimeters in width and for strips (3) of 300 millimeters in width ; in each of these ranges, the exact adjustment to the concrete width of the strip (3) used is effected by adjusting the width by means of the actuator (15) in each case.

According to one embodiment, the stops (16) which give the guide width of greater width are provided fixed in the movable end parts of the corresponding composition of the guides (13) and (14); while the stops (16.1) which give the range of smaller width are provided removable, so that it suffices to remove these stops (16.1) to establish in each case the corresponding guide width for the strip (3) that we're going to use.

On the other hand, the aforementioned guides (13) and (14) are provided with a respective actuator (17) by means of which each of them can be moved as a unit towards the sides, thus being able to adjust the position to ensure perfect centering in relation to the alignment of the tape application (3), in order to avoid the errors that any deviation from the alignment would cause.

The reel holder (1) on which is mounted the reel (2) which carries the strip (3) to be applied comprises shells (18) which are movable in the radial direction for securing the coil (2) during assembly, or to leave this fixation free for disassembly, this radial movement of the shells (18) occurring by axial displacement of a central axis (19) provided with conical grooves ( 20), with which the supports (21) of the above-mentioned shells (18) cooperate, as can be seen in FIG. 4.

This displacement of the central axis (19) is effected by means of an actuator (22) which, according to the direction of rotation, actuates the displacement in one direction or the other.

The reel holder (5) receiving the paper support strip (3.2) in turn comprises a central axis (23) which can be moved by means of an actuator (24) and which is provided with conical grooves with which to cooperate the corresponding shell supports (25) movable in the radial direction, by means of which the corresponding reel (4) for receiving the paper strip (3.2) is fixed.

The reel holder (1) further comprises an actuator (26) by means of which the entire block of said reel holder (1) can be moved in the axial direction, thereby allowing perfect centering of the strip (3) from the proper alignment. This adjustment of the centered positioning of the strip (3) with the actuator (26) of the reel holder (1), as well as the adjustment of the centering in this same direction, by means of the actuators (17) of the guides (13) and (14), can be manual, but it can also be achieved by an automatic control actuation by means of an installation equipped with the means suitable for this.

In the area in which the strip (3) flows from the supply reel (2) to the application area, there are arranged cutting means with which the upper layer of composite (3.1) is cut. the strip (3), as planned for the application. The actuation of said cutting means is fully automatic, its operation being controlled from a control box (27) disposed on the support (28) of the head.

These cutting means are constituted by two knife-holder mechanisms (29) and (30), which are arranged, according to FIGS. 7, 8 and 9, in an assembly comprising a longitudinal displacement on respective screws (31), and a actuation by means of corresponding actuators (32), and can in turn be moved in height on corresponding guides (33) and with actuation by means of respective actuator cylinders (34). The rotation of said mechanisms (29) and (30) for cutting actuations is actuated by corresponding motors (35), which actuate the rotary movement of the knife holder axis by means of a rack and pinion transmission.

With this arrangement of mobility and actuation, the aforementioned mechanisms (29) and (30) allow cuts to be made with absolute precision and in any trajectory, by completely cutting the upper layer of the composite (3.1) in the cuts. so that the scraps to be removed are easily detached and without significantly affecting the paper support strip (3.2) so that the latter does not break and remains whole downstream of the application area to be collected on the spool (4).

For the working process of applying the strips of composite (3.1) on the corresponding surfaces, the head is arranged with rotary mounting of the support (28) relative to a vertical axis, by actuation by means of a transmission (36 ), and in tilting mounting on its own support (28), by coupling the transmission to a respective crown (37), according to FIGS. 1, 2 and 3.

The transmission (36) of the rotary actuation and the coupling of the transmission on the crown (37) provided for the tilting actuation are effected by means of a set of two drive pinions, one of the pinions actuation in action in one direction and the other actuation in the other direction, so that one obtains a total precision of movements, without play in the inversion of movements.

The speed of the strip (3) in its movement from the supply reel (2) to the application area is controlled by an encoder transfer roller (38), visible in Figures 1 and 2 and shown in FIG. 16, which performs, by means of the appropriate means, a command control of the motor actuation of the conveyor of the strip (3), by making the corrections necessary to maintain constant the speed of said strip (3 ) upon arrival at the application area, by compensating for the variations in said speed which the reduction in diameter and volume of the supply coil (2) tend to cause as a result of consumption, so that the process of The application on work surfaces is completely uniform.

In addition, there is also a control on the strip (3) by means of two boxes (39) provided with detector photodiodes (40) (FIG. 15), which are arranged in the zone of passage of said strip (3). toward the application area, as seen in Figures 1 and 2, so that said photodiodes (40) inspect completely the surface of the strip (3) and, when they detect any defect in the upper layer of composite (3.1), cause the device to stop, thus preventing a defective area from being applied to the surface of work.

Claims (7)

1. Tape laying unit for depositing bands of composite, of the type formed by a rotating assembly which can be tilted, comprising compacting means intended to press a band (3) consisting of an upper layer of composite (3.1) and a paper backing sheet (3.2) and which derives from a feed spool (2), the compacting means consisting of a press (6) and a pressure part (7) which can both be tilted between two respective working and withdrawal positions, the press (6) coming into action first to fix the upper composite layer (3.1.) of the band (3) onto the application surface, while the pressure part (7) comes into subsequent action pressing the composite layer (3.1) with force against the corresponding surface to conduct compacting, characterized in that:
   the press (6) and pressure part (7) are arranged so that they can be actuated independently and successively on the application zone, the press (6) being mounted on a tilting support (8) which can be caused to tilt by means of actuator cylinders (10) to provide the working and withdrawal positions of said press (6), and the pressure part (7) being mounted on a tilting support (9) which can be caused to tilt by means of actuator cylinders (11) to provide working and withdrawal positions of said pressure part (7), while other cylinders (12) come into action to forcefully press said pressure part against the application surface in the working position.
2. Tape laying unit for the application of bands of composite as in claim 1, characterized in that, when travelling towards the feed zone, the band (3) passes over conductor guides (13) and (14) provided with a pressurized air supply to avoid friction, whose width can be adjusted by means of corresponding actuators (15) to adjust to the width of band (3) used, and are also mounted on a mobile assembly having lateral movement which enables positioning by means of corresponding actuators (17) for centring relative to the alignment of application of the band (3).
3. Tape laying unit for the application of bands of composite as in claim 1 or 2, characterized in that the feed spool (2) of the band (3) is mounted in a spool holder (1) arranged in a mounting movable in the axial direction and which can be moved by means of an actuator (26) for centre positioning relative to the alignment of application of the band (3).
4. Tape laying unit for the application of bands of composite as in any of the preceding claims, characterized in that in connection with the passing of the band (3) towards the application zone, cutting means are arranged formed of two blade-holder mechanisms (29) and (30) which can be driven in longitudinal movement by means of screws (31), moved upwards through actuation of cylinders (34) and actuated in rotation around the blade-holder axis by means of corresponding motors (35).
5. Tape laying unit for the application of bands of composite as in any of the preceding claims, characterized in that in connection with the passing of the band (3) towards the application zone, a coding transfer roller (38) is arranged which gives feed actuation command of the band (3) to maintain a constant arrival speed of the band (3) in the application zone.
6. Tape laying unit for the application of bands of composite as in any of the preceding claims, characterized in that in connection with the passing of the band (3) towards the application zone, boxes (39) fitted with detector photodiodes (40) are arranged which perform inspection of the band (3) to halt the application process when any defect is detected in the composite (3.1.) of said band (3).
7. Tape laying unit for the application of bands of composite as in any of the preceding claims, characterized in that transmission of rotating and tilting actuation of the tape laying unit assembly is performed in both cases by a double drive gearwheel which sets actuation in action in one direction and in the other by means of different respective gearwheels, cancelling out slack when movement is reversed.